Antiwear hydraulic oil

ABSTRACT

An improved antiwear hydraulic oil comprises major amounts of a mineral lubricating oil (preferably a hydrocracked oil which has been solvent extracted to improve ultra-violet light stability) and minor amounts of a &#39;&#39;&#39;&#39;secondary&#39;&#39;&#39;&#39; zinc dialkyl dithiophosphate antiwear agent, chelating type and film forming type metal deactivators, a neutral barium salt of a petroleum sulfonate and a succinic acid based rust inhibitor. The hydraulic oil is especially useful in lubrication of high output (e.g., 100 gallons per minute) bronze-on-steel axial piston pumps.

United States Patent n 1 Newingham et al.

[4 1 Dec. 2, 1975 l l ANTIWEAR HYDRAULIC OIL [73] Assignee: Sun OilCompany of Pennsylvania, Philadelphia. Pa.

[221 Filed: Oct. 31, 1974 [21] Appl. No.: 519,728

[52] US. Cl. 252/32.7 E; 252/33; 252/75 [5]] Int. Cl. C10M 1/48; ClOM3/42;C1OM 5/24; ClOM 7/46 [58] Field of Search 252/327 E, 33, 75

[56] References Cited UNITED STATES PATENTS 2,369 632 2/l945 Cook ct al252/327 E $640,872 2/1972 Wiley ct al. 252/327 E 3,652,4l0 3/1972Hollingshurst et al. 252/327 E Foncher ct al. 252/327 E Lyle ct a].252/327 E Primary ExaminerDelbert E. Gantz Assistant Examinerl. VaughnAttorney, Agent, or Firm-George L. Church; J. Edward Hess; Barry A.Bisson [57] ABSTRACT An improved antiwea'r hydraulic oil comprises majoramounts of a mineral lubricating oil (preferably a hydrocracked oilwhich has been solvent extracted to improve ultra-violet lightstability) and minor amounts of a secondary" zinc dialkyldithiophosphate antiwear agent, chelating type and film forming typemetal deactivators, a neutral barium salt of a petro leum sulfonate anda succinic acid based rust inhibitor. The hydraulic oil is especiallyuseful in lubrication ofhigh output (e.g.. 100 gallons per minute)bronzeon-steel axial piston pumps.

10 Claims, No Drawings ANTIWEAVR HYDRAULIC 01 BACKGROUND OF THEINVENTION Zinc dithiophosphates are widely used in lubricants asanti-wear agents. Although ashless anti-wear materials have been gainingprominence because of the absence of heavy metals, the zincdithiophosphates still continue to, provide one of the most economicalsources of anti-wear protection. There are three general types of zincdithiophosphates from which to select, depending on the specificapplication. The zincs are classified as either primary, secondary, oraryl, depending on the alcohols from which they are made, although theprimary and secondary zincs are commonly referred to as alkyl. If theR-O- group in the structure for zinc dithiophosphate (shown below) isderived from a primary alcohol, then the zinc is referred to as primary;likewise, ifit is derived from a secondary alcohol, it is referred to assecondary and, if derived from an alkylated phenol, it is referred to asaryl.

Each of these zincs usually displays a different combination ofperformance properties as summarized below:

Performance Type of Zinc Dithiophosphate Characteristic PrimarySecondary Aryl Wear Protection Ave rage Best Poorest OxidationInhibition Average Best Poorest Thermal Stability Average Poorest BestDemulsibility Best Average Poorest- Cost Lowest Average Highest Based ontheir relative performance levels, zincs are selected for a particularapplication. For example, aryl zincs are used almost exclusively indiesel engine oils because of their excellent thermal stability. Primaryzincs find a large application in both engine oils and hydraulic oils.Secondary zincs are used mostly in hydraulic oils, transmission and gearoils. Primary and secondary zincs have been selected fortheseapplications because of their relatively good anti-wear performance,good anti-oxidant qualities and low. cost. Where hydraulic oils areconcemed, primary zincs have usually been preferred because they offeredthe best overall performance for the lowest cost.

However, problems have been encountered when primary zincs are used incertain axial in-line piston pumps. in these pumps, the bronze pistonpads slide on 2 a steel swash plate. With certain zinc-containingantiwear hydraulic oils, a reaction occurred at the interface of thebronze piston pads and the steel swash plate. The reaction productsraised the friction level between the sliding surfaces and eventuallygenerated enough heat to crack the swash plate.

The present invention provides an anti-wear hydraulic oil containing asecondary zinc and which provides superior performance in vein pumps andpiston pumps and especially with such bronze-on-steel pumps.

SUMMARY OF THE INVENTION An improved anti-wear hydraulic oil comprisesmajor amounts of a mineral lubricating oil (preferably a hydrocrackedoil which has been solvent extracted to improve ultra-violet lightstability) and minor amounts of a secondary zinc dialkyl dithiophosphateanti-wear agent, chelating type and film forming type metaldeactivators, a neutral barium salt of a petroleum sulfonate and asuccinic acid based rust inhibitor. The hydraulic oil is especiallyuseful in lubrication of high output (e.g., gallons per minute)bronze-on-steel axial piston pumps. 1

The preferred mineral oils consist mainly of oils termed paraffinic orrelatively paraffinic by the viscosity gravity constant classification.Especially useful are the stabilized, hydrocracked oils described incopending U.S. Pat. applications Ser. No. 178,193 filed Sept. 7,1971 andSer. No. 298,126, filed Oct. 16, 1972 of Bryer et al. (the entiredisclosure of which, and of Ser. No. 35,231 below is incorporatedherein). Blends of such hydrocracked oils with a naphthenic acid-freenaphthenic distillate can also be used on the present invention. Thepolymer and .soap type antileak hydraulic oils shown in Ser. No. 35,231of Griffith et al. (filed May 6, 1970 and now abandoned) can also bemade containing the secondary zinc dialkyl dithiophosphates, foranti-wear, if the two types of metal deactivator, a neutral bariumsulfonate and a succinic acid type rust inhibitor are includedtherewith.

The relative proportions of the essential ingredients are important. Theweight ratio of the secondary zinc dialkyl dithiophosphate to the totalweight of the deactivator compounds is generally no greater than about15 to I (typically about 10 to l). l l

The relative weight proportions of the succinic acid inhibitor and theneutral barium petroleum sulfonate are generally in the range of 3 to 1to l to I (typically about 2 to l). The relative proportion ,of theneutral barium petroleum sulfonate to the total metal deactivators isalso important (and is best determined by experiment) since if therelative amount of the barium compound is too great, the hydrolyticstability of the lubricant will be poor and high metal losses will beencountered in use in the pump.

FURTHER DESCRIPTION To predict which kinds of zinc dithiophosphateswould cause swash plate cracking two test procedures are useful. One thebeverage bottle hydrolytic stability test, measures thecorrosive natureof the zinc-containing hydraulic oil in terms of metal loss and totalacidity. This test, as described in the ASTM handbook, also calls forthe amount of insolubles produced, the viscosity change of the oil, andthe acid number of the oil. For this particular hydraulic oil problem,however, these data are notpertinent.

The other, the sludge and metal corrosion test, also measurescorrosiveness in terms of metal loss, but measures sludge produced aswell. The sludge and metal corrosion test is a combination oxidation andcorrosion test. This test is run using the same conditions as the 5 ASTMD 943 test. After a thousand hours, however, the test is terminated andthe oil is analyzed for the total amount of sludge present, as well asthe amounts of copper and iron present in the combined oil, water andsludge fractions.

Before the beverage bottle hydrolytic stability test and the sludge andmetal corrosion tests were adopted to separate good and badzinc-containing hydraulic oils, preliminary work was done using the lowvelocity friction apparatus to compare a secondary zinc formulationwhich performed satisfactorily in piston pump service with a primaryzinc formulation which did not. This comparison gave the firstindication that there might be a significant difference between primaryand secondary zinc hydraulic oil formulations in lubrication of abronze-steel piston pump.

The low velocity friction apparatus is an instrument which measuresfriction characteristics as a function of sliding speed and appliedload. For most testing, a steel anulus is used which rotates on a steelplate. Both the anulus and plate are immersed in the test oil. Tosimulate the sliding conditions of the bronze-on-steel piston pump,however, a bronze anulus and a steel plate was used. In this case,testing was aimed at generating reaction products, rather than frictioncurves. At the end of the test the used oil was analyzed for coppercontent and also visually inspected. As shown by the results below, theprimary zinc formulation showed a significant increase in coppercontent, indicating a substantial 35 amount of reaction products. Thesecondary zinc formulation, however, showed little change. Even moredramatic was the difference in appearance of the two formulations at theend of the test. The primary zinc showed very severe accumulation ofblack reaction products; the secondary formulation remained clear.

Low Velocity Friction Apparatus Test Oil Data Copper Content, ppm

Conditions: Bronze-on steel specimens. ZOOF, 80 lbs. load,

8 ft/minutes sliding speed. [7 hours.

These were fully formulated anti-wear hydraulic oils containing. inaddition to zinc din" rust and The beverage bottle hydrolytic stabilitytest and the sludge and metal corrosion test have been adopted as partof the anti-wear hydraulic oil specification for the bronze-on-steelaxial piston pumps by certain pump manufacturers and the Military underthe MlL specification 24459. The hydrolytic stability test is an ASTM-established test and is found in the current ASTM handbook under ASTM D2619-67. In the test, grams of the anti-wear hydraulic oil are added to25 grams of distilled water in a beverage bottle containing a copperstrip. The bottle is capped and placed in an oven where it rotates endover end at 5 rpm for 48 hours at 200F. At the end of the test, theweight loss of the copper strip and the total acidity of the water layerare determined. They are considered a measure of the corrosiveness ofthe oil. Those anti-wear hydraulic oils which produce no more than 0.5mg/cm of copper loss and no more than 6.0 mgKOH' total acidity in thewater portion are considered satisfactory for bronze-on-steel pistonpump use, provided, of course, that they also satisfy the otherrequirement--the sludge and metal corrosion test. This test is acombination oxidation and corrosion test. It is run using the sameconditions as the more familiar ASTM D 943 Turbine Oil Oxidation Test.At the end of a 1000 hours, however, the oxidation test is terminatedand the oil is analyzed for total sludge produced, as well as the copperand iron content of the combined oil, water, and sludge portions.Maximum acceptable limits for the test are:

Total insoluble sludge, mg 40f) Total Copper, mg 200 Total iron, mg

Complete description of the test is found under Federal Test Method3,020.l.

With the results of the LVFA preliminary testing in mind, we evaluatedthe same primary zinc and secondary zinc formulations in the hydrolyticstability and sludge and metal corrosion tests. The results are shown inTable 1. Note the converse relationship between the two zincs in the twotests. The primary zinc-containing formulations shows relatively poorhydrolytic stability primarily because of high metal loss which webelieve is the more crucial part of this test. It does, however, performwell in the sludge and metal corrosion test. The secondaryzinc-containing formulation, on the other hand, performed in theopposite fashion. It did relatively well in hydrolytic stability, butpoorly in sludge and metal corrosion test.

The poor hydrolytic stability of this particular general-purpose primaryzinc was not unique. The hydrolytic stability of two other similargeneral-purpose primary zincs was examined and relatively high metalloss was found. These are identified as B and C in Table II. Also shownin Table II is a secondary zinc, E, which shows the same degree of metalloss as the general-purpose primaries, indicating that the relativelylow metal loss of the secondary reference zinc was not characteristic ofall secondary zincs.

One feature which these two tests do have in common is that they bothmeasure metal loss. Both the primary and secondary zinc were showingmetal loss, although in different forms. Howcver, we discovered that thecombined use of two types of metal deactivators can minimize metal loss.

There are two common types of metal deactivators. One, the film-formingtype, minimizes metal corrosion by plating out on the metal surface. Ineffect, this puts a protective barrier between the metal surface and thecorrosive materials. The second type of deactivator reduces metal lossby chelating or tieing up the corrosive materials before they cancatalyze further attack on the surfaces.

When the same primary and secondary zinc formulations as above areformulated using-various types of metal deactivators, the results areshown in Table Ill. Table III shows that 1. None of the deactivatorsimproved the performance of the general-purpose primary zincdithiophosphates sufficiently to pass the hydrolytic stability test.

2. Both the chelating and combination type of metal deactivators wereeffective enough on the secondary zinc formulation for it to pass thehydrolytic stability test. The improvement in minimizing metal loss wassubstantial. Although the chelating metal deactivator was more effectivethan the combination type in improving hydrolytic stability, it had beenlinked to compatibility problems in earlier work. Therefore, thecombination type was preferred because of its better compatibility. Asshown in Table IV, this deactivator was also effective in dramaticallyreducing the sludge and metal corrosion of the secondary zincformulation.

These results show that the primary zinc should not be used informulations where hydrolytic stability was required. The secondary zincformulation was clearly superior. However, this lubricant is stilldefective and requires for satisfactory performance the surface activecomponent, namely, two specific types of rust inhibitors.

Although the use of the two combined metal deactivators represents amajor means of improving the hydrolytic stability of the secondary zincformulation, a far more successful lubricant is obtained by the properselection of rust inhibitors. The effect of various types of rustinhibitors on the secondary zinc in the presence .and absence of thecombination type metal deactivator is shown in TableVl. Unlike theformulations shown in Table VI, these blends were not fully formulated,but contained only the components shown. Note that both the acidic andneutral type rust inhibitors which are surface active enough to provideadequate protection as measured by the ASTM D 665B test, also reactedwith the zinc to promote severe metal attack in the hydrolytic stabilitytest. The dibasic rust inhibitor which did not provide adequate rustprotection, however, did not promote metal attack. The presence of thecombination type metal deactivator did not substantially change theseresults. Where the deactivator did produce a significant change,however, was in the case of the mixed rust inhibitors which consisted ofboth acidic and neutral components used separately before. Withoutdeactivator, metal attack occurred, but in the presence of deactivator,metal attack was reduced within the acceptable limits with no loss ofrust protection. Obviously, the combination of the acidic and neutralcomponents provides a balanced rust inhibitor which is surface activeenough to protect against rust, but not active enough to overpower themetal deactivator.

With some commercially available secondary zinc dialkyldithiophosphates, a precipitate or haze will form when an effectiveamount of the combination of the two types of metal deactivators isincorporated therein. For example, such a precipitate formed with E.This precipitate formation should be used as a screening test todetermine the better secondary zincs" for use in the present invention.

Based on the results discussed above, it can be seen that the reactivityof zinc dithiophosphates, particularly in combination with othercomponents, has a significant effect on the bronze/steel metallurgyfound in some piston pumps. Specifically, these results indicate that:

l. The secondary zinc reference formulation performed satisfactorily inthe axial piston pump because it is less reactive than the generalpurpose primary zinc tested. These, being more reactive,

6 are unsuited for use in bronze-on-steel axial piston pumps.

2. The film-forming, chelating, and combination types of deactivatorswere not effective in reducing metal loss in hydrolytic stabilitytesting of the primary zinc examined. However, the chelating andcombination type deactivators were effective in reducing metal loss ofthe secondary zinc formulation. i

3. That rust inhibitors which are surface active enough to provide goodrust protection can react with the secondary zinc to promote severemetal attack in the hydrolytic stability test. The presence of acombination type deactivator is not effective in these cases.

4. That the use of a mixed acidic-neutral type rust inhibitor with thecombination type metal deactivator provides adequate rust protectionwithout promoting metal attack.

Commercially available primary zinc dialkyl dithiophosphates arewell-known and include Amoco 5959, B 103 and Oronite 269N. Similarly,there are many commercially available secondary zinc dialkyldithiophosphates, e.g., Lubrizol 677A" (the reference or D of thepresent case), Lubrizol i097, and Edwin Cooper Hitec E653 (identified asE herein).

The commercially available chelating type metal deactivators includeAmoco (an alkyl derivative of 2,5-di-mercapto-l,3,4-thiadiazole) and therelated compounds" in US. Pat. Nos. 2,719,125; 2,719,126 and 2,983,716.

The commercially available film-forming type metal deactivators includethe benzotriazoles (e.g., Vanderbilt BT Z and US. Rubber Company Cobrate99), and the Vanderbilt products Cuvan 80" (N,N'-disalicylidene-l,2propane-diamine, 80% in organic solvent), Cuvan 7676and Cuvan XL.

The commercially available neutral barium petroleum sulfonates-includeNaSul BSN of R. T. Vanderbilt Co.

The commercially available acidic type rust inhibitors are primarilysubstituted-succinic anhydrides (e.g., TPSA or tetraphenyl succinicanhydride).

Accordingly, the following example is illustrative of lubricants whichcan be produced in accordance with the present invention.

ILLUSTRATIVE EXAMPLE An additive mixture, for use in formulation ofantiwear hydraulic oils containing a secondary dialkyl dithiophosphate,was made by blending the following ingredients:

Weight "71 ditertiary butyl paracresol 20.0 naphthyl amine 20.0 zincdiamyldithiocarbamate 3.0 tetraphenyl succinic anhydride 2.2 neutralbarium petroleum sulfonate [.5 Amoco 150" chelate-type deactivator 3.3Cuvan 80 film-forming deactivator 6.7 diluent. paraffinic oil 43.3

The additive mixture was blended as indicated below to make an anti-wearhydraulic oil:

COMPOSITION. VOLUME 71 UV stable hydrocracked oil 99.23 Secondary ZDP(D") 0.40 Additive mixture 0.35 Silicone antifoam 0.02

The hydrocracked oil had an SUS viscosity at 100F of 200, an ASTM VI ofabout 100 and was paraffinic by VGC class. The properties (and typicalcontrol limits) of the blend (in metric units) follow:

TYPICAL RANGE TESTS METHOD MlN. MAX. EXAM- PLE # Viscosity, cSt/37.8CD445 42.9 46.2 44.6 Viscosity, cSt/40C D341 40.2 Viscosity, cSt/98.9CD445 6.50 Viscosity, cSt/100C D341 6.33 Viscosity lndex D2270 100 106Flash COC, C D92 204 235 #Pour, C D97 18 -18 Color D1500 2.0 0.5Density/c, kg/m D1298 873 861 Total Acid No., mgKOH/g D664 1.0 CopperStrip, 3 hrs/100C D130 1 l Sulfur, D2622 0.14 Conradson Carbon, D1890.25 An line Point, C D611 112 #Demu1sibi1ity/54.4C D 1401 Separation,minutes 30 25 #Foam, Tendency/Stability D892 Sequence 1, cm 50/0 25/0Sequence 11, cm 50/0 25/0 Sequence 111, cm 50/0 25/0 #Rust, Syn. SeaWater D6658 Pass Pass Oxidation Stability, hr. D943 2000 2000Continental Oxid.,hr. 100 100 4-Ball Wear Scar, mm kg, 1800 rpm, 54.4C,0.35 1hr #Appearance Visual Bright Bright #Zinc, wt.% .044 .054 .048Phosphorous, wt.% D 1091 .039 .051 .044 #DBPC, wt.% .070 .087 .077

When non-hydrocracked solvent refined paraffinic oils are substitutedfor the hydrocracked oil, 0.50% of the mixture is required forequivalent performance.

Similarly, blends of hydrocracked and non-hydrocracked lubes can be usedin the present example, as can unstabilized hydrocrac ked oils; however,in general the UV. stabilized (by solvent extraction or hydrorefining)hydrocracked lube provides the best performance at lower additivelevels.

Similarly, blends (as of 100 and 500 SUS,- at 100F) of oils can besubstituted for the 200 SUS base oil and higher or lower viscosity baseoils (e.g., 80-2000SUS) can be used, as in this example, to makehydraulic oils of varied viscosities.

In commercial additives, the type and amount of ZDP can vary from brandto brand of additive; however, in a given lubricant formulation, theamount of a given ZDP can be determined by calculation from the zinccontent. As a rule of thumb, such substitutions are done by the zincequivalent method. In the above example,'the amount of additive shouldincorporated in the range of 0.044 to 0.054 Zn (typically 0.048 wt. Inthe work reported in the Tables, the ZDP additives were used at aboutthe same Zn levels. The representative secondary ZDP, Lubrizol 677A(sometimes identified as D) analyzes 9.25 wt. Zn and 8.5 wt. P.

Compositions according to the present invention can be made wherein theviscosity of the base petroleum oil is in the range of 3,000 SUS at100F. In general, for use as a hydraulic oil the typical base oilviscosity will be below 1,000 SUS at 100F.; however, lubricantsconsisting essentially of a 1,000-3,000 SUS at 100F base oil are usefulas gear lubricants (e.g., see Ser. No. 477,872, filed June 10, 1974, ofWilliams, Reiland and Griffity, the entire disclosure of which isincorporated herein).

The terms compatible amount and mutually compatible amounts as usedherein mean that no precipitate is observed in the final lubricant whenit is stored for 24 hours at about F. 1

Federal 3020.1 Results Sludge & Metal Corrosion Insoluble Sludge. mg 400198 921 Metals in Combined Oil Water & Sludge Copper, mg 200 76 306Iron, mg 13 341 Zinc dialkyldithiophosphate The base oil, in all tablesherein, was 200 SUS, at 100F, U.V stabilized (by solvent extraction)hydrocracked oil (ASTM V1 about 100), available commercially as SunparLW or "HPO 200", from the Sun Oil Company. The lubricant contained 0.5vol.

1 of the ZDP, 0.07 wt. ditertiary butyl paracresol, 0.07

wt. naphthalamine, 0.006 vol. NaSul BSN, 0.0088 vol. TPSA, 0.012 zincDiamyldithiocarbamate (Vanlube AZ), and 2 ppm active silicon antitoam.

Table I1 COMPARISON OF THE HYDROLYTIC STABILITY OF ZDP LUBRlCANTSMaximum Acceptable Primary Formulations Secondary Formulation TestLimits (A) (B) (C) (D) (E) Beverage Bottle Hydrolytic Stability Test,ASTM D 2619 CopperWeight Loss,

mg/cm' 0.5 3.5 t 1.5 2.4 0.5 2.09 Total Acidity of Water Layer, mgKOH6.0 6.2 33.0 2.5 8.9 1.20

The lubricants of this Table (11) are fully formulatedanti-wear'hydraulic oils, similar to Table 1. containing, in addition toZDP (0.5 vol. 7: antioxidant, rust inhibitor, and defoamer.

Table III EFFECT OF METAL DEACTIVATOR'S IN HYDROLYTIC STABILITY OF ZDPLUBRICANTS Combination of Maximum Film-Forming & Acceptable Film-FormingType Chelating Type Chelating Types Test Limits Primary SecondaryPrimary Secondary Primary Secondary Beverage Bottle Hydrolytic StabilityTest (ASTM D 2619) Fail Fail Fail Pass Fail Pass Copper Weight Loss.

mg/cm 0.5 0.61 i 0.33 2.59 0.0 4.25 0.03 Total Acidity of Water Layer.mgKOH 6.0 10.0 17.0 6.21 1.7 1.6 3.1 Formulations were similar to thoseof Table I.

Table IV EFFECT OF COMBINATION TYPE METAL DEACTIVATOR ON HYDROLYTICSTABILITY AND SLUDGE AND METAL CORROSION TESTS OF SECONDARY ZDP (D)Maximum Acceptable Deactivator Deactivator Test Method Limits AbsentPresent Beverage Bottle Hydrolytic ASTM Stability Test D 2619 Copper Wt.Loss, mg/cm 0.5 0.5 0.03 Total Acidity of Water Layer, mgKOH 6.0 8.9 3.1Sludge and Metal Corrosion Federal 3020.1 Insoluble Sludge, mg 400 921288 Metals in Combined Oil.

Water and Sludge Copper, mg 200 306 173 Iron. mg 100 341 57 Formulationssimilar to those of Table I.

Table V EFFECT OF METAL DEACTIVATORS 1N HYDROLYTIC STABILITY TESTING (2)(3) F ilm-Forming Type Chelating-Type Combination of (benzotriazole)(mercapto-thiodiazole) Film-Forming and Chelating Types PrimarySecondary Primary Secondary Primary Secondary Metal Deactivator (A) (D)(A) (D) (A) (D) Beverage Bottle Hydrolytic Stability Test (ASTM D 2619)Fail Fail Fail Pass Fail Pass Copper Weight Loss.

E/ 0.61 0.33 2.59 0.0 4.25 0.03 Total Acidity of Water Layer. mgKOH 10.017.0 6.2 1.7 1.6 5.6

"R. T. Vanderbilt BTZ" "Amoco 150" il T. Vanderbilt OD 691" Formulationswere similar to those of Table I Table VI EFFECT OF RUST INHIBITORS ONREFERENCE SECONDARY ZINC DITHIOPHOSPHATE Secondary Zinc Secondary ZincSecondary Zinc Secondary Zinc Secondary Zinc without and TPSA" andNeutral Ba" and Dibasic Acid and Mixed Rust Inhibitor Rust InhibitorRust Inhibitor Rust Inhibitor Rust Inhibitor TBS! Metal DeactivatorMetal Deactivator Metal Deactivator Metal Deactivator Metal DeactivatorHydrolytic Beverage Bottle Absent Present Absent Present Absent PresentAbsent Present Absent Present Stability Test (ASTM D 2619) Copper WeightLoss,

mg/cm 0.26 0.40 3.29 2.04 2.67 4.29 0.37 0.45 1.87 0.17 -Total Acidityof Water Layer. mgKOH 2186 1.80 11.78 14.0-1- 1.68 0.56 1.18 1.40 2.243.37 Rust Protection. Synthetic Sea Water (ASTM D 6658) Fail Fail PassPass Pass Pass Fail Fail Pass Pass Basic Formulation 0.40 vol. 7! zincdithiophospbate in 200 SUS/100 F paraffinic base oil (solvenbcxtructedafter hydrocracking) rust inhibitors. 0.10 volume 7:. Combination ofacid 'I'PSA" and neutral "Ba" (barium petroleum sulfonate) rustinhibitors.

The invention claimed is:

l. A composition, useful as an anti-wear hydraulic oil or as a gearlubricant, comprising major amounts of a mineral lubricating oil andminor, effective and mutually compatible amounts of a secondary zincdialkyl dithiophosphate anti-wear agent, chelating type and film formingtype metal deactivators, and, as rust inhibitors, a neutral barium saltof a petroleum sulfonate and an alkyl or aryl substituted succinic acidor acid anhydride.

2. The composition of claim 1, wherein said mineral lubricating oilconsists essentially of oil having an SUS viscosity at 100F. in therange of 60-3,000 SUS and a viscosity-gravity constant in the range of0.7800.819.

3. The composition of claim 1, wherein said chelating type metaldeactivator is an alkyl-substituted derivative of2,5-di-mercapto-1,3,4-thiodiazole.

4. The composition of claim 1 wherein said filmforming type metaldeactivator is N,N-disalicylidene- 1,2-propane-diamine.

5. The composition of claim 3 wherein said filmforming type metaldeactivator is N,N-disalicylidene- 1,2-propane-diamine.

6. The composition of claim 1 wherein one said rust inhibitor istetraphenyl succinic anhydride.

7. The composition of claim 5 and containing tetra phenyl succinicanhydride 8. The composition of claim 7 wherein said lubricant is usefulas a hydraulic oil and contains effective and compatible minor amountsof a naphthyl amine, zinc Dialkyldithiocarbamate and ditertiary butylparacresol.

9. The composition of claim 8 wherein said base oil consists essentiallyof one or more hydrocracked oils having a viscosity gravity constantbelow about 0.80 and which have been stabilized against degradation byultra violet light by extraction with an aromatic selective solvent.

10. The composition of claim 9 and containing an effective amount of anantifoaming agent.

1. A COMPOSITION, USEFUL AS AN ANTI-WEAR HYDRAULIC OIL OR AS A GEAR LUBRICANT, COMPRISING MAJOR AMOUNTS OF A MINERAL LUBRICATING OIL AND MINOR, EFFECTIVE AND MUTUALY COMPATIBLE AMOUNTS OF A SECONDARY ZINC DIALKYL DITHIOPHOSPHATE ANTI-WEAR AGENT, CHELATING TYPE AND FILM FORMING TYPE METAL DEACTIVATORS, AND, AS RUST INHIBITORS, A NEUTRAL BARIUM SALT OF A PETROLEUM SULFONATE AND AN ALKYL OR ARYL SUBATITUTED SUCCINE ACID OR ACID ANHYDRIDE.
 2. The composition of claim 1, wherein said mineral lubricating oil consists essentially of oil having an SUS viscosity at 100*F. in the range of 60-3,000 SUS and a viscosity-gravity constant in the range of 0.780-0.819.
 3. THE COMPOSITION OF CLAIM 1, WHEREIN SAID CHELATING TYPE METAL DEACTIVATOR IS AN ALKYL-SUBSTITUTED DERIVATIVE OF 2,5-DIMERCAPTO-1,3,4-THIODIAZOLE.
 4. The composition of claim 1 wherein said film-forming type metal deactivator is N,N''-disalicylidene-1,2-propane-diamine.
 5. The composition of claim 3 wherein said film-forming type metal deactivator is N,N''-disalicylidene-1,2-propane-diamine.
 6. The composition of claim 1 wherein one said rust inhibitor is tetraphenyl succinic anhydride.
 7. THE COMPOSITION OF CLAIM 5 AND CONTAINING TETRA PHENYL SUCCINIC ANHYDRIDE.
 8. The composition of claim 7 wherein said lubricant is useful as a hydraulic oil and contains effective and compatible minor amounts of a naphthyl amine, zinc Dialkyldithiocarbamate and ditertiary butyl paracresol.
 9. The composition of claim 8 wherein said base oil consists essentially of one or more hydrocracked oils having a viscosity gravity constant below about 0.80 and which have been stabilized against degradation by ultra violet light by extraction with an aromatic selective solvent.
 10. The composition of claim 9 and containing an effective amount of an antifoaming agent. 